test
node1
BFO:0000003
occurrent
node1->node1
node2
BFO:0000015
process
node1->node2
node3
GO:0008150
biological_process
node2->node3
node4
GO:0050896
response to stimulus
node3->node4
node8
GO:0042221
response to chemical
node4->node8
node5
GO:0010033
response to organic
substance
node6
GO:0014070
response to organic
cyclic compound
node5->node6
node7
BFO:0000001
entity
node7->node1
node8->node5